The blizzard of attack ads, the waves of outside money and the phalanx of national operatives and press descending on New York’s 26th district all attest to the fact that Tuesday’s special election has taken on special meaning. Political agnostics exposed only to the campaign commercials would be forgiven for assuming the race pitted Nancy Pelosi against Paul Ryan in a cage match for the future of the Republic, rather than a state assemblywoman against a local county clerk in a race for a congressional seat that might vanish in redistricting. But it isn’t all hyperbole. The first election since House Republicans passed Paul Ryan’s budget has become a referendum on the two parties’ differing visions of the fate of Medicare and a potential bellwether for races nationwide in 2012.

Recent polls suggest Democrat Kathy Hochul has nosed ahead of Republican Jane Corwin in the contest’s waning stages. A Siena College survey conducted last week showed Hochul with 42% to 38% lead over Corwin, with Jack Davis–a former Democratic candidate running on the Tea Party ticket–taking 12% of the vote. A second survey conducted by Public Policy Polling, a Democratic firm, found Hochul up six points. In a preview of the Democrats’ 2012 playbook, Hochul has steadily hammered Corwin for backing Ryan’s budget, which would replace Medicare with private-insurance subsidies that wouldn’t keep pace with rising health-care costs. The backlash from the vote has spurred Hochul’s surge. In the Siena poll, 21% of voters cited the program as the predominant factor in the race, exceeding even the 20% who said the top issue was jobs. Seniors expressed a favorable view of Hochul by 56% to 36%, and an unfavorable view of Corwin by a 51% to 40% margin.

Even if Corwin squeaks through, Democrats believe the pitched battle in a reliably conservative district prefigures Republicans’ vulnerability on the issue in 2012. Former Congressman Chris Lee, who resigned in scandal after the married Republican posed as a lobbyist and sent shirtless photos of himself to a potential Craigslist date, won 74% of the vote last November in the district, one of four Empire State precincts to break for John McCain in 2008. Carl Paladino, who captured 34% of the vote statewide in November’s gubernatorial election after a campaign marked by antigay remarks, racist email-forwards and a proposal to convert prisons into dormitories where welfare recipients would receive training in issues like personal hygiene, won 61% in the the district. “Even in an overwhelmingly Republican district like NY-26, voters are rejecting the Republican plan to end Medicare,” Jesse Ferguson, a spokesman for the Democratic Congressional Campaign Committee, wrote in an e-mail to TIME. “Democratic House Republicans who voted to end Medicare should be very worried about losing independent voters and seniors in 2012.”

Corwin, who says she would have voted for Ryan’s budget, is struggling to embrace its spirit while distancing herself from its particulars. “It’s starting a conversation that we absolutely have to have, but I’m not married to it,” she told Politico of the Republican budget. At a debate earlier this month, she called it “a plan we can make some changes to, that can be tweaked, absolutely.”

It’s an awkward contortion. Ryan’s budget isn’t a hypothetical proposal subject to tweaks and revisions. It earned the blessing of all but four House Republicans. But GOPers with an eye on the polls–the results of which have underlined the political peril in overhauling Medicare–have been backpedaling on the plan even as supporting it becomes a litmus test for any politician hoping to win the support of the conservative base. Ryan’s work “is the foundation upon which Republican fiscal policy will be developed for this era,” Newt Gingrich, who became intimately acquainted with the risks of publicly bashing the Wisconsin Republican’s plan, wrote TIME in an e-mail last week. From the presidential primary on down, Republicans seeking office will have to parry criticism for their Medicare vote without straying too far from the party line.

Like her peers, Corwin has argued that Ryan’s budget would preserve the program, while the status quo favored by Democrats would ensure its erosion. A recent report from the program’s trustees suggested Medicare could reach insolvency in 2024, five years earlier than expected. Corwin, whose family grew wealthy from building a phone-book business, has poured some $3 million of her own money into the race, while conservative outside groups like American Crossroads and the Chamber of Commerce have chipped in with six-figure ad buys. Democratic counterparts, like the recently formed House Majority PAC, have funneled cash to Western New York as well, though not as much. One print ad, disseminated by a pro-Democrat union group, depicts an elderly man holding the hand of his bedridden wife on one side and blasts Corwin’s Medicare stance on the other, above an illustration of a benefits card set ablaze.

The wildcard in the race is Davis, a three-time Democratic candidate running on the Tea Party ticket. “Jack Davis’ presence is the only reason why a candidate as flawed as Kathy Hochul could find herself in a competitive position in this district,” says Paul Lindsay, a spokesman for the National Republican Congressional Committee. Davis pledged to spend $3 million of his own money on the race, and preaches a brand of protectionism that resonates with some residents of a white, middle-class district reeling from the decline of the region’s manufacturing base. Wary of his ability to siphon off conservative votes by wrapping himself in a Gadsden flag, Republicans have repeatedly attacked Davis as a Democrat in disguise; one ad depicts Hochul and him as Pelosi’s puppets. But both the Siena and PPP polls indicate that Davis’ share of the vote is shrinking as the Democrats’ Medicare messaging catches on.

As the race neared the finish line, both parties deployed a spate of high-profile surrogates. John Boehner trooped up to the district, as did the Empire State’s two Democratic U.S. Senators. The GOP enlisted ascendant national Republicans like Chris Christie and Marco Rubio to endorse Corwin, while Bill Clinton and Andrew Cuomo went to bat for Hochul.

Democrats are eager to claim that a Corwin loss on Tuesday would augur doom next year for supporters of Ryan’s plan who hail from genuine swing districts. Republicans rightly caution against drawing sweeping conclusions from a single race, but some acknowledge that GOP candidates must find a way to neutralize the criticism they’ll face over Medicare. “It’s drummed up some interest in [the Democratic] base that we’re going to have to deal with,” says a Republican operative. “To a certain extent this may be a good wake-up call for us.”